Resveratrol Attenuates Heat-Stress-Impaired Immune and Inflammatory Responses of Broilers by Modulating Toll-Like Receptor-4 Signaling Pathway

Abstract

This study investigated the effect of resveratrol on the immune and inflammatory responses and the mRNA levels of splenic toll-like receptor (TLR)-4 signaling pathway-related genes of broilers under heat stress (HS). One hundred and sixty-two birds were allocated to three groups, each with 6 replicates, for 21 continuous days. The three treatments were as follows: the control group (22 ± 1 °C), the HS (33 ± 1 °C for 10 h d -1 and 22 ± 1 °C for the remaining time) group and the HS + resveratrol (400 mg kg -1 ) group. At the end of the trial, one bird per replicate close to the average body weight (BW) was selected, exsanguinated, and slaughtered. Compared with the control group, the HS treatment decreased (p<0.05) final BW, average daily gain (ADG), average daily feed intake (ADFI), relative weight of bursa of Fabricius and spleen, serum immunoglobulin (Ig) Y, IgA and interleukin (IL)-10 contents, and splenic IL-10 mRNA level, while it increased (p<0.05) feed/gain, mRNA levels of splenic tumor necrosis factor-α (TNF-α), TLR-4, nuclear factor-kappa-B (NF-κB), IL-1β, and IL-6. Compared to the HS group, the HS+resveratrol group exhibited increased (p<0.05) final BW, ADG, relative weight of bursa of Fabricius and spleen, serum IgY, IgA and IL-10 contents, and splenic IL-10 mRNA level, while it exhibited lower (p<0.05) TNF-α, IL-1β and IL-6 contents in serum, and splenic TLR4, TNF-α, IL-1β, and NF-κB mRNA levels. In conclusion, resveratrol prevented a HS-impairment of the immune function of broilers by blocking the abnormal activation of the TLR4 signaling pathway.

Effects of medical plants on alleviating the effects of heat stress on chickens

“…Of the dual immune reactions, the adaptive and innate response, the adaptive reaction is more multifaceted and involves prolonged immunological challenge ( Mashaly et al 2004 ; Amedy et al, 2011 ; Bilal et al, 2021 ; Ringseis and Eder, 2022 ). Serum immunoglobulin G ( IgG ), and secretory immunoglobulin ( SIgA ) were significantly decreased in heat stressed broilers ( Li et al, 2023b ). SIgA and IgG are 2 main kinds of immunoglobulin in chickens that show a role in maintaining immunity.…”

“…Numerous studies have reported the harmful effects of HS on immunological responses ( Amedy et al, 2011 ; Farag and Alagawany, 2018 ; Sun et al, 2023 ). HS is responsible for inhibiting the phagocytic activity of leukocytes and suppressing the biosynthesis of B and T lymphocytes ( Li et al, 2023b ). The heterophil to lymphocyte ratio ( H/L ratio) is a popular signal of stress in broilers ( Al-Murrani et al, 2006 ).…”